Pollution is characterized by the dispersion of low concentrations of compounds and harmful substances in the environment, whose treatment of high volumes is hampered both by the technical and economic point of view, particularly when they are solubilized in the medium (molecular level dispersion). For example, the amount of minerals containing noble metals concentrates is becoming increasingly scarce due to its spread in the environment due to their applications both in industry and in mass consumer products. Thus, it becomes increasingly necessary the development of materials and processes that allow for the concentration and recovery of elements dispersed in even smaller quantities, currently on the pollutant level, e.g. in water bodies.
Currently, costly processes are used for removing contaminants from water, particularly when it comes to soluble species that do not readily precipitate or are removed by oxidation or by means of conventional treatments. These processes involve steps such as pH correction, flocculation and subsequent removal of the resulting flocculated material, generating potentially toxic waste (and often transferring the problem of water pollution to another form of tailings, e.g. solid waste), making use of slow processes of sedimentation, sand filtration, and/or the use of expensive filter elements with limited lifespan. Thereat, they can be subjected to treatments with oxidants such as chlorine, ozone or hydrogen peroxide to remove pathogens and eventually, soluble species. However, metal ions and other contaminants may still remain after all treatments, keeping the water inadequate for drinking or discarding. Still, conventional treatments often leave large volumes of contaminated solid waste, like sludge, requiring the correct disposal of that waste in landfills, suitable storage locations or incineration.
The anteriority search revealed some relevant documents that will be described below.
Document CN102527332 reveals a magnetic compound adsorption material, and the preparation and implementation processes. The magnetic adsorbent composite material, comprising pulverized activated charcoal particles and nanometric iron oxide mixed on the surface or internal parts of micrometric particles. The material is useful for the sewage treatment by means of magnetic separation. The activated carbon particles and nanometric Fe3O4 mass ratio in the magnetic adsorbent composite material is 4:1 to 5:3, and the size of the magnetic adsorbent composite material is 100 micra to 1 mm. The composite material described in the document differs from the current due to the fact that this one is characterized by the use of 4 to 10 nm nanoparticles deposited preferentially on the surface of the activated charcoal.
The document WO2012099445 reveals a porous adsorbent which is impregnated with magnetite, ferrihydrite, goethite or Hematite. The porous adsorbent is the activated charcoal, zeolite or pulverized alumina. The said document also details the porous adsorbent manufacturing, which involves immersing the porous adsorbent in a liquid phase which includes magnetite, ferrihydrite, goethite or hematite, porous adsorbent exposure to alkaline solution to form pores in the sedimentation, heating, washing and drying phases. Also details the water treatment method that uses the porous adsorbent. Among the compounds removed from water are natural organic matter, calcium and sodium ions.
The document details the CN101940910 composite material for adsorption of the magnetic separation type that comprises nanometer iron oxide (Fe3O4) and active carbon fiber. The synthesized composite material can be used as adsorbent material of the magnetic separation type to adsorb organic and inorganic pollutants to purify waste water. The present invention differs from this document since it does not use substrate from carbon fiber based on polyacrylonitrile and a unique production process.
The US20120186980 document details a device comprising a capacitor which includes a porous nanometric structure and metal oxide nanoparticles arranged over the nanometric porous structure. The preferred metal oxide is the ferric oxide and the preferred porous nanometric structure are the carbon nanotubes. The device can be used to separate ions of a fluid to remove arsenate, arsenite and sodium from the water. The present invention differs from this document due to the fact that it does not use carbon nanotubes as the porous medium and the objective of the US20120186980 is a device for removing the water ions.
Thus, it may be observed as per the above detailed that there a necessity of new adsorbent materials which can be produced in greater quantity and in a simplified way that will reduce the production costs. Additionally, it may be observed the necessity of improved adsorbent materials that can be separated from the medium where they are scattered in a simplified way, allowing the regeneration in order to make its reuse possible. This will increase the efficiency in the applications of the adsorbent material.
As per the literature available, it was not found documents anticipating or suggesting the teachings of the present invention, so the solution proposed here has novelty and inventive steps according to the prior art.